Treatment of chemoresistant ovarian cancer with sigma2/SMAC and cisplatin.

e16508 Background: Platinum resistance continues to be a major barrier to the successful treatment of ovarian cancer. Overexpression of the X-linked inhibitor of apoptosis proteins (XIAP) contribute to platinum resistance in ovarian cancer through inhibition of caspases and up regulation of Akt activity. Second mitochondrial-derived activators of caspases (SMAC) is an endogenous protein that binds to and reverses XIAP-mediated inhibition of caspases. In order to exploit the SMAC-mediated pro-apoptotic pathway pharmacologically, SMAC mimetics have been developed and shown to induce apoptosis in cancer cells in vitro and in vivo. Untargeted cytotoxic cancer drugs bind to both malignant and normal tissue leading to significant toxicity. We have shown previously that solid tumors upregulate the sigma-2 receptor. We have also shown that sigma-2 ligands are internalized into cancer cells and are therefore an appealing vehicle for tumor targeted therapy. The goal of this study is to test if a conjugate drug of sigma-2 ligand and a SMAC mimetic (sigma-2/SMAC) in combination with chemotherapy is capable of overcoming chemoresistance in ovarian cancer. Methods: SKOV3 and OVCAR3 ovarian cancer cell lines were treated with sigma2/SMAC (1-16μM) and/or cisplatin (.5-10μg/mL). Viability assays were used to detect cell death. Luminescence-based caspase assays were used to compare the activity of caspase-3, -7, and -9 between treatment groups to document involvement of the XIAP survival pathway. Results: We found that sigma2-SMAC is synergistic when used in combination with cisplatin. Compared to untreated cells, SKOV3 cells treated with sigma/2SMAC (4uM), cisplatin .5ug/mL, or combination therapy showed 52.6%, 117.7%, and 34.8% viability respectively (p<.05). Cisplatin and sigma2/SMAC remained synergistic at increasing doses. Similar results were observed in OVCAR3 cells. Caspase-3 and -7 increased in combination therapy 1.2-fold over Sigma/2SMAC alone (4uM) and 7-fold over cisplatin alone (.5ug/mL) in SKOV3 cells (p<.05). Conclusions: This study suggests that the sigma2/SMAC conjugate provides a targeted means for overcoming chemoresistance in ovarian cancer through inhibition of XIAP and activation of caspases.

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Overexpression of glycosyltransferase 8 domain containing 2 confers ovarian cancer to CDDP resistance by activating FGFR/PI3K signalling axis

Oncogenesis ◽

10.1038/s41389-021-00343-w ◽

2021 ◽

Vol 10 (7) ◽

Author(s):

Shuting Huang ◽

Suiying Liang ◽

Guandi Chen ◽

Jing Chen ◽

Keli You ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Affinity Purification ◽

Chemotherapy Resistance ◽

Growth Factor Receptor ◽

Ovarian Cancer Cells ◽

Platinum Resistance ◽

Signaling Axis

AbstractIt has been reported that chemotherapy resistance mainly contributed to treatment failure and poor survival in patients with ovarian cancer. Therefore, clarifying the molecular mechanism and identifying effective strategies to overcome drug resistance may play an important clinical impact on this malignant tumor. In our study, we found that the expression of Glycosyltransferase 8 domain containing 2 (GLT8D2) was significantly upregulated in ovarian cancer samples with CDDP (Cis-dichlorodiammine-platinum) resistance. Biological experiment demonstrate that GLT8D2 overexpression confers CDDP resistance on ovarian cancer cells; however, inhibition of GLT8D2 sensitized ovarian cancer cell lines to CDDP cytotoxicity both in vitro and in vivo. By using affinity purification/mass spectrometry (IP/MS) and reciprocal co-immunoprecipitation (co-IP) analyses, we found that GLT8D2 interacts with fibroblast growth factor receptor 1(FGFR1) in ovarian cancer cells. Furthermore, overexpression of GLT8D2 activated FGFR/PI3K signaling axis and upregulated the phosphorylation levels of FRS2a and AKT (AKT serine/threonine kinase). Importantly, pharmacological inhibition of FGFR and PI3K (phosphatidylinositol 3-kinase) signaling pathway significantly counteracted GLT8D2-induced chemoresistance and enhanced platinum’s therapeutic efficacy in ovarian cancer. Therefore, our findings suggest that GLT8D2 is a potential therapeutic target for the treatment of ovarian cancer; targeting GLT8D2/FGFR/PI3K/AKT signaling axis may represent a promising strategy to enhance platinum response in patients with chemoresistant ovarian cancer.

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Targeting Dormant Ovarian Cancer Cells In Vitro and in an In Vivo Mouse Model of Platinum Resistance

Molecular Cancer Therapeutics ◽

10.1158/1535-7163.mct-20-0119 ◽

2020 ◽

Vol 20 (1) ◽

pp. 85-95

Author(s):

Zhiqing Huang ◽

Eiji Kondoh ◽

Zachary R. Visco ◽

Tsukasa Baba ◽

Noriomi Matsumura ◽

...

Keyword(s):

Ovarian Cancer ◽

Mouse Model ◽

Cancer Cells ◽

Ovarian Cancer Cells ◽

Platinum Resistance

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DDP-resistant ovarian cancer cells-derived exosomal microRNA-30a-5p reduces the resistance of ovarian cancer cells to DDP

Open Biology ◽

10.1098/rsob.190173 ◽

2020 ◽

Vol 10 (4) ◽

pp. 190173 ◽

Cited By ~ 1

Author(s):

Ronghua Liu ◽

Yucan Zhang ◽

Peiwen Sun ◽

Changxiu Wang

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Quantitative Polymerase Chain Reaction ◽

Luciferase Reporter ◽

Ovarian Cancer Cells ◽

Important Conclusion ◽

Skov3 Cells ◽

Potential Strategy

Exosomes carrying microRNAs (miRNAs) have been demonstrated to play critical roles in the regulation of development, growth and metastasis of cancer. Bioinformatic predictions identified differentially expressed SRY-box 9 (SOX9) in OC, and the regulatory miRNA miR-139-5p. Here, we aim to evaluate the function of exosomal miR-139-5p in the sensitivity of ovarian cancer (OC) cells to cis-diamminedichloroplatinum(II) (DDP). Expression pattern of miR-139-5p and SOX9 in ovarian cancer cells (SKOV3) and DDP-resistant cells (SKOV3/DDP) was identified using reverse transcription quantitative polymerase chain reaction and western blot analysis. The relationship between miR-139-5p and SOX9 was validated using a dual-luciferase reporter assay. SKOV3/DDP cell line was developed and introduced with miR-30a-5p mimic to analyse the effects of miR-30a-5p on resistance to DDP. The in vitro and in vivo effects of exosomal miR-30a-5p on resistance of SKOV3 cells to DDP were assessed in a co-culture system of exosomes and OC cells as well as in tumour-bearing nude mice. High expression of SOX9 and low expression of miR-30-5p were witnessed in OC. Furthermore, miR-30-5p, a downregulated miRNA in SKOV3/DDP cells, increased the rate of cell apoptosis and enhanced the sensitivity of SKOV3/DDP cells to DDP by targeting SOX9. Moreover, exosomes carrying miR-30a-5p were identified to sensitize SKOV3/DDP cells to DDP both in vitro and in vivo . These data together supported an important conclusion that DDP-resistant OC cell-derived exosomal miR-30a-5p enhanced cellular sensitivity to DDP, highlighting a potential strategy to overcome drug resistance.

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Toosendanin Shows Potent Efficacy Against Human Ovarian Cancer through Caspase-Dependent Mitochondrial Apoptotic Pathway

The American Journal of Chinese Medicine ◽

10.1142/s0192415x2150083x ◽

2021 ◽

pp. 1-16

Author(s):

Ge Wang ◽

Xiu-Qi Fan ◽

Lu Li ◽

Yan Li ◽

Bian Shi ◽

...

Keyword(s):

Ovarian Cancer ◽

Caspase 3 ◽

Dependent Manner ◽

Caspase 9 ◽

Apoptotic Pathway ◽

Mitochondrial Apoptotic Pathway ◽

Invasion And Migration ◽

Skov3 Cells ◽

Parp 1

Toosendanin (TSN) is a triterpenoid extracted from the bark or fruits of Melia toosendan Sieb et Zucc, which is a traditional Chinese medicine and mainly grows in China and India. TSN has been verified to possess antitumor activities on various human cancers, whereas the effects of TSN on ovarian cancer (OC) has not been reported yet. Here, TSN was shown to significantly inhibit proliferation of SKOV3 and OVCAR3 cell lines in a dose- and time-dependent manner. Treatment of OC cells with TSN resulted in colony formation reduction, S and G2/M phase arrest, cell apoptosis, and dramatic decrease in mitochondrial membrane potential. Furthermore, TSN suppressed invasion and migration of OC cells. Research on molecular mechanism indicated that the above efficacy of TSN was associated with decreased expression of survivin, PARP-1, Bcl-2, Bcl-xl, caspase-3, caspase-9, MMP-2 and MMP-9 and increased expression of cleaved PARP-1, Bax, cleaved caspase-3 and cleaved caspase-9. Finally, in vivo results showed that TSN suppressed OC xenograft tumor growth by inducing apoptosis and regulating the related protein expression levels of SKOV3 cells in transplanted tumors. Taken together, our data provide new insights into TSN as a potentially effective reagent against human OC through caspase-dependent mitochondrial apoptotic pathway.

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Emerging Roles for Ion Channels in Ovarian Cancer: Pathomechanisms and Pharmacological Treatment

Cancers ◽

10.3390/cancers13040668 ◽

2021 ◽

Vol 13 (4) ◽

pp. 668

Author(s):

Concetta Altamura ◽

Maria Raffaella Greco ◽

Maria Rosaria Carratù ◽

Rosa Angela Cardone ◽

Jean-François Desaphy

Keyword(s):

Ovarian Cancer ◽

Ion Channels ◽

Transient Receptor Potential ◽

Critical Role ◽

Gynecologic Cancer ◽

Receptor Potential ◽

Transient Receptor Potential Channels ◽

Platinum Resistance

Ovarian cancer (OC) is the deadliest gynecologic cancer, due to late diagnosis, development of platinum resistance, and inadequate alternative therapy. It has been demonstrated that membrane ion channels play important roles in cancer processes, including cell proliferation, apoptosis, motility, and invasion. Here, we review the contribution of ion channels in the development and progression of OC, evaluating their potential in clinical management. Increased expression of voltage-gated and epithelial sodium channels has been detected in OC cells and tissues and shown to be involved in cancer proliferation and invasion. Potassium and calcium channels have been found to play a critical role in the control of cell cycle and in the resistance to apoptosis, promoting tumor growth and recurrence. Overexpression of chloride and transient receptor potential channels was found both in vitro and in vivo, supporting their contribution to OC. Furthermore, ion channels have been shown to influence the sensitivity of OC cells to neoplastic drugs, suggesting a critical role in chemotherapy resistance. The study of ion channels expression and function in OC can improve our understanding of pathophysiology and pave the way for identifying ion channels as potential targets for tumor diagnosis and treatment.

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Plasma cells shape the mesenchymal identity of ovarian cancers through transfer of exosome-derived microRNAs

Science Advances ◽

10.1126/sciadv.abb0737 ◽

2021 ◽

Vol 7 (9) ◽

pp. eabb0737

Author(s):

Zhengnan Yang ◽

Wei Wang ◽

Linjie Zhao ◽

Xin Wang ◽

Ryan C. Gimple ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Plasma Cell ◽

Plasma Cells ◽

Ovarian Cancer Cells ◽

Mesenchymal Phenotype ◽

Ovarian Cancers ◽

Novel Approach

Ovarian cancer represents a highly lethal disease that poses a substantial burden for females, with four main molecular subtypes carrying distinct clinical outcomes. Here, we demonstrated that plasma cells, a subset of antibody-producing B cells, were enriched in the mesenchymal subtype of high-grade serous ovarian cancers (HGSCs). Plasma cell abundance correlated with the density of mesenchymal cells in clinical specimens of HGSCs. Coculture of nonmesenchymal ovarian cancer cells and plasma cells induced a mesenchymal phenotype of tumor cells in vitro and in vivo. Phenotypic switch was mediated by the transfer of plasma cell–derived exosomes containing miR-330-3p into nonmesenchymal ovarian cancer cells. Exosome-derived miR-330-3p increased expression of junctional adhesion molecule B in a noncanonical fashion. Depletion of plasma cells by bortezomib reversed the mesenchymal characteristics of ovarian cancer and inhibited in vivo tumor growth. Collectively, our work suggests targeting plasma cells may be a novel approach for ovarian cancer therapy.

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Splicing factor USP39 promotes ovarian cancer malignancy through maintaining efficient splicing of oncogenic HMGA2

Cell Death and Disease ◽

10.1038/s41419-021-03581-3 ◽

2021 ◽

Vol 12 (4) ◽

Author(s):

Shourong Wang ◽

Zixiang Wang ◽

Jieyin Li ◽

Junchao Qin ◽

Jianping Song ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Malignant Tumors ◽

Splicing Factor ◽

Ovarian Cancer Cells ◽

Nuclear Speckles ◽

Aberrant Expression ◽

Intergenic Regions

AbstractAberrant expression of splicing factors was found to promote tumorigenesis and the development of human malignant tumors. Nevertheless, the underlying mechanisms and functional relevance remain elusive. We here show that USP39, a component of the spliceosome, is frequently overexpressed in high-grade serous ovarian carcinoma (HGSOC) and that an elevated level of USP39 is associated with a poor prognosis. USP39 promotes proliferation/invasion in vitro and tumor growth in vivo. Importantly, USP39 was transcriptionally activated by the oncogene protein c-MYC in ovarian cancer cells. We further demonstrated that USP39 colocalizes with spliceosome components in nuclear speckles. Transcriptomic analysis revealed that USP39 deletion led to globally impaired splicing that is characterized by skipped exons and overrepresentation of introns and intergenic regions. Furthermore, RNA immunoprecipitation sequencing showed that USP39 preferentially binds to exon-intron regions near 5′ and 3′ splicing sites. In particular, USP39 facilitates efficient splicing of HMGA2 and thereby increases the malignancy of ovarian cancer cells. Taken together, our results indicate that USP39 functions as an oncogenic splicing factor in ovarian cancer and represents a potential target for ovarian cancer therapy.

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